Some watercraft, typically referred to as jet boats, are propelled by one or more jet propulsion units located at the back of the watercraft. A jet propulsion unit pressurizes water to create thrust. In a jet propulsion unit, water is first scooped from under the hull, is then pressurized by an impeller, and is finally expelled through a venturi. The venturi converges to increase the speed of the jet of water being expelled by the jet propulsion unit. The jet pump unit also includes a steering nozzle in alignment with the venturi. To steer the watercraft, the steering nozzle is turned to redirect the jet of water being expelled from the venturi. Some jet boats are also provided with a reverse gate for each one of its jet propulsion units. When actuated, a reverse gate redirects the jet of water being expelled by the steering nozzle under and toward a front of the watercraft so as to create a rearward thrust to cause the jet boat to move in a reverse direction.
As is the case with any vehicle operating in water, following the application of a force on it (i.e. thrust), a jet boat tends to remain in motion for some time since the water offers little resistance to its movement. Since turning of the jet boat can only be achieved in combination with a forward or rearward thrust, the above tendency of a jet boat to maintain its momentum can make delicate manoeuvring, such as docking the jet boat, somewhat challenging to some boaters. The above situation is exacerbated by the fact that such manoeuvring sometimes need to be made in areas where there are water currents.
Therefore, there is a need for a jet propulsion unit that can be used to facilitate manoeuvring of watercraft such as jet boat.